Long-chain urea compounds in detergent compositions



United States Patent LONG-CHAIN UREA COMPOUNDS 1N DETERGENT COMPOSITIONSJohn Ross, Ramsey, N. J., assignor to Colgate-Palmolive Company, JerseyCity, N. J., a corporation of Delaware No Drawing. Application May 2,1951, Serial No. 224,264

12 Claims. (Cl. 252-137) The present invention relates to new syntheticdetergent compositions, and, more particularly to compositions of thetype of the anionic sulfated and sulfonated detergents having improvedproperties.

There has been a considerable amount of research to discover substancesor additives which aid the eflicieucy of detergent compositions. Theproblem is exceedingly complex, however, in view of the variousphysico-chemical mechanisms or properties and the like involved in theaction of a detergent composition including suspension, interfacialtension, micellar structure, dispersion, foam stability, etc. and thegeneral difliculty usually in determining the particular mechanism whichis being altered by changes in the formulation of detergentcompositions.

During recent years, synthetic detergents of the type of the organicsulfates and sulfonates have been developed which have properties whichrender them highly advantageous for certain uses. In general, theexploration for suitable additives or builders for synthetic detergentcompositions of the type of the anionic sulfates and sulfonates has beendirected by the requirements of increased foaming and/or detersivepower. While the exact relationship, if any, between foaming anddetergency is not known, it is highly desirable that these detergentcompositions exhibit excellent foaming properties, in addition to a highlevel of detersive efficiency, particularly for consumer appeal andcertain home and industrial uses. In view of the complex nature of boththe foam and detergency phenomena, the character of such non-soapsynthetic detergents, and the many other variables in detergentcompositions, additives in general exhibit a certain degree ofspecificity of action.

Urea and certain lower derivatives thereof have been used with certainsurface-active agents chiefly in large proportions as cheap andinnocuous fillers and as solubilizing agents. Certain other derivativeshave been used as intermediates in the manufacture of resins,plastieizers, emulsifying agents, pharmaceuticals, etc.

It has now been discovered that the presence of a substituted ureahaving a long-chain alkyl radical in detergent compositions consistingessentially of anionic sulphated and sulphonated detergent is effectiveto achieve a significant enhancement in surface-active properties suchas detergency and foaming. More particularly, the improved detergentcompositions consist essentially of water-soluble sulphated orsulphonated detersive salts, and as an organic builder 2. minorproportion of a higher alkyl substituted urea effective to enhance theaction of the detergent composition in aqueous solution. Theseimprovements are unique since such urea derivatives by themselves havepoor foaming and deterging properties, and thus are valueless ascleaning agents per se.

Illustrative of the enhancing additives of the present in vention arethe higher alkyl substituted urea compounds characterized by limitedwater-solubility. These derivatives may be additionally substituted withlow-molecular weight aliphatic radicals, such as lower alkyl and alkylolgroups. The higher alkyl substituent may be branched 2,708,183 PatentedMay 10, 1955 or straight-chain in structure; it comprises moreover suchgroups as octyl, docyl, dodecyl, keryl, pentadecyl, and hexadecyl, mixedlong-chain alkyls derived from longchain fatty materials, crackedparaffin wax olefins, polymers of monoolefins, etc. This higher alkylsubstituent will generally be from at least about 8, generally up toabout 18 carbon atoms, and preferably about 10 to about 14 carbon atoms.

Included within the ambit of the invention is the following preferredclass of compounds suitable as additives which may be represented by thestructural formula:

wherein R is a long-chain higher alkyl radical. Suitable examples ofsuch compounds are octyl urea, decyl urea, dodecyl urea, cocyl ureawherein the cocyl substituent is a mixture of essentially long-chainalkyls derived from mixed coconut oil fatty acids, dodecyl urea whereinthe dodecyl group is derived from a propylene tetramer, teradecyl urea,myristyl urea, pentadecyl urea wherein the pentadecyl group is derivedfrom a propylene pentamer, hexadecyl urea, etc.

An additional suitable class is the polyalkyl substituted ureas havingone alkyl group long-chain in structure as indicated, and at least onelower alkyl group. The lower alkyl groups should have a total generallyof not in excess of about six carbon'atoms. It is preferred that eachlower alkyl group be not in excess of about three carbon atoms each.These polyalkyl derivatives may be symmetrical or unsymmetrical.Specific examples Within this class are N dodecyl, N methyl urea; Ndodecyl N methyl urea; N dodecyl, NN' dimethyl urea; N tetradecyl Nethyl urea; etc.

A further class is the higher alkyl substituted ureas having at leastone lower alkylol group, the carbon atom range being the same as withthe lower alkyl groups. The alkylol group may be monoor polyhydroxy instructure. Suitable examples are N dodecyl N methylol urea; N dodecyl Nethanol urea; N dodecyl NN diethanol urea; N dodecyl N butanol urea; Ntetradeeyl N 2, 3 dihydroxy propyl urea; etc.

These various urea derivatives may be prepared in any suitable mannerand numerous processes for the production of alkyl ureas, mixedpolyalkyl and alkyl-alkylol ureas, etc., and their analogues are Wellknown in the art.

The novel compositions of the present invention contain as the activeingredient the anionic sulphated and sulphonated detergents, includingsuitable mixtures thereof. Included therein are the aliphatic sulphatedor sulphonated agents, such as the aliphatic acyl-containing compoundswherein the acyl radical has about 8 to about 22 carbon atoms, and, moreparticularly, the aliphatic carboxylic ester type, containing at leastabout 10 and preferably about 12 to about 26 carbon atoms to themolecule. Among the aliphatic detersive compounds, it is preferred touse the sulphated aliphatic compounds having about 12 to about 22 carbonatoms. As suitable examples of aliphatic detergents may be found thesulphuric acid esters of polyhydric alcohols incompletely esterifiedwith higher fatty acids, e. g. coconut oil monoglyceride monosulphate,tallow di-glyceride monosulphate; the long chain pure or mixed higheralkylsulphates, e. g. lauryl sulphate, cetyl sulphate, higher fattyalcohol sulphates derived from coconut oil; the hydroxy sulphonatedhigher fatty acid esters, e. g. higher fatty acid esters of 2,3di-hydroxy propane sulphonic acid; the higher fatty acid esters of lowmolecular weight alkylol sulphonic: acids, e. g. oleic ester ofisethionic acid; the higher fatty acid ethanolamide sulphates; thehigher fatty acid amides of amino alkyl sulphonic acids, e. g. lauricamide of taurine, and the like.

It is a feature of this invention that the effects are particularlyenhanced with the alkyl aryl sulphonate detergents. These aromaticsulphonate detergents are also known in the art. They may be mononuclearor polynuclear in structure. More particularly, the aromatic nucicus maybe from benzene, toluene, xylene, phenol, cresols, naphthalene, etc. Thealkyl substituent on the aromatic nucleus may vary Widely, as long asthe desired detergent power of the active ingredient is preserved.

More specific examples of suitable alkyl aromatic sulphonate detergentsare the higher alkyl aromatic sulphonates. The higher alkyl substituentmay vary in the. manner described for such groups in the higher alkylurea additives. Thus, it may be branched or straightchain in structure,and comprise decyl, dodecyl, keryl, mixed long-chain alkyls frompolymeric lower monoolefins, etc. Preferred examples of this class arethe higher alkyl mononuclear aryl sulphonates wherein the alkyl grouphas about 8 to about 22, and preferably about 12 to about 18 carbonatoms. More particularly, it is preferred to use the higher alkylbenzene sulphonates wherein the higher alltyl group averages about 12 toabout 16 carbon atoms. For example, propylene may be poly.- merized tothe tetramer and condensed with benzene in the presence of aFriedel-Crafts catalyst to yield essentially the dodecyl benzenederivative which is suitable for sulphonation to the desired sulphonatecompounds.

These various anionic detergents are generally used in the form of theirwater-soluble salts, such as the alkali metal, alkaline earth metal,ammonium, amine, and

- alkylolamine salts. While the sodium, potassium, am-

monium and alkylolamine (e. g. mono-, di-,' and triethanolamine) saltsare preferred ordinarily, other salts such as the lithium, calcium, andmagnesium salts may be used if desired. For general use, it isordinarily preferred to use the sodium and potassium salts. For certainspecialized uses, it may be preferred to select the ammonium andalkylolamine salts in view of their generaliy greater solubility inaqueous solution. The concentration of these water-soluble salts(including suitable mixtures thereof) in the detergent compositions ofthe present invention is generally at least about 10% by 1 weight oftotal solids, and preferably from about l50%.

With'built compositions, particularly in particulate form, an activeingredient content of 10-50%, and preferably about l40% yields highlysatisfactory results. Compositions With very high concentrations ofthese active ingredients are prepared for specialized uses generally.Thus in liquid detergent compositions, any suitable concentrations maybe employed, e. g. 90% of total solids or about 20 to about 60% oftheweight of the total'liquid detergent composition.

The amount of the substituted urea additives in the detergentcomposition is generally minor in proportion to the weight of die activeingredient and effective in producing the desired improvements indetersive capacity and/or foaming power.

to about 2:1. It is preferred that the additive be from about 5 to aboutof the active ingredient. In particulate detergent compositions theadditive will usually be from about /2 to about 15% by weight of thedetergent composition. Particularly effective results have been achievedwherein the additiyes are present in amounts of the order of about 1 to10% of the total detergent composition. It is preferred usually to useabout 1-5% additive however. The optimum amount of additive and itsratio to the active ingredients will vary according to the specificmaterials, the contemplated field of application and manner of use.

The additives may be incorporated with the active ingredient at anypoint during the manufacturing process 7 Generally, the proportion ofactive ingredient to additive should be from about:l

at which subsequent operations will not adversely modify the propertiesof the detergent compositions. A variety of procedures which have provedto be convenient, economical, and productive of best results are: theadditives may be added to a hot aqueous slurry of about 40 to 50% solidsconcentration comprising the active ingredient with vigorous stirring toform a smooth, uniform and homogeneous paste, the additives may bedissolved in a suitable solvent and added to the slurry of the activeingredient, a mixture or emulsion of the additives in Water with a minorproportion of the active ingredient may be incorporated into the slurry,or the additive may be incorporated in the detergent composition by apost treatment to spray-dried detergent particles, etc.

Thereafter, these compositions may be prepared in the form of solutions,pastes or as dry or partially hydrated solid products, preferably in afinely divided condition. It is preferred to prepare the products inparticulate form. Accordingly, the slurry of the detergent compositionmay be subjected to any suitable drying operations and converted toparticle form. The mixture may thus be subjected to conventionalspray-drying, roll-drying or drumdrying operations utilizingtemperatures above, about 212 F. to obtain homogeneous detersiveparticles.

The additives, exert their primary detersive effects on an activation ofthe soil removal power. Such results may be illustrated by theapplication of soil removal tests, using a testing procedure whichinvolves the uniform soiling, washing with particular detergentcompositions at F. :2 F., and drying of a large number of cottonswatches. The whiteness of the various test swatches is measured by aHunter reflectometer. The units of soil removed may be calculated bysubtracting the average reflectivity of unwashed control samples fromthe washed swatches. The results'on soiled wool swatches may bedetermined using substantially the same testing procedure.

Table I indicates thepercent increased reflectance as a measure ofimproved soil removal, on cotton and wool swatches using a standarddetergent composition consisting essentially of 20% sodium salts ofdodecyl benzene sulfonate (the dodeeyl group being derived from apropylene tetramer), 40% sodium tripolyphosphate, 3% sodium carbonateand 37% sodium sulfate at 0.4% concentration in soft tap water, with andwithout added cocyl urea additive. The percentages listed in'the tablefor each concentration of additive represent the percent change inwhiteness reflectance using an standard the above detergent compositionwithout organic additive. A value indicates the approximate improvedwhiteness reflectance as a measure of improved soil removal and a valuerepresents decreased soil removal in comparison to the standard.

The marked improvement in soil removal due to the presence of thesubstituted urea additives is evident from the data. It is apparent thaton cotton soil, optimum'results are achieved using about 2-5% of theadditive with this particular detergent composition. On wool soil, the

effects are much more marked, with synergistic improvement effected atall concentrations and optimum results at 3-10% additive. Thesignificance of the presence of these additives is even more strikingsince the above compositions containing the additive and about 20%detergent is much more effective generally in soil removal thancompositions containing for example 35% detergent without the additive.

However, for each specific type additive, as for each detergentcomposition, there is an optimum proportion or concentration which maybe determined by routine tests. A few representative additives in theidentical detergent composition referred to above yield the followingresults by the same procedure:

Table II 0.25% concentration at 115 F. with the number of greased plateswashed by the formula A without additive being taken as a standard of100%. The result with gfi'iggfiii Formula B is tabulated in terms ofpercent of thestand Additive Percent Cotton Wool Table IV Foam 2 +15 +30Endurance 1. Dodecyl urea 3 +34 +50 Composition in Dish- 4 +29 +56washing, 2. Decyl urea 2 +10 +38 percent 2 ii iii Octyl urea 7 $15 +42 A1oo 10 +74 B Another feature is that the improved results may be 30 Theunusual effect obtained by Composition- B conexhibited both in hard andin soft water, and over a wide range of washing concentrations. Whileadditives in general exert widely variable effects in hard and softwater, the novel compositions of the present invention are effective inboth types, thereby enlarging their field of application to a greatdegree. The wide range of suitable washing conditions under which theimproved results are obtained is significant also since it permitseconomy of use and allows a wide latitude to the consumer and the likeas to suitable quantities to be employed.

Table IH illustrates the percent improvement in soil removal at 0.25%,0.4%, and 0.75% concentrations of the self same detergent composition inhard water of 300 p. p. m. hardness using only 1.5% of dodecyl ureaadditive on cotton swatches.

Table III Percent Concentration of Detergent Composition gig? Removal0.25 percent..... +10 0.40 percent +6 0.76 percent +9 The results areeven more marked using other selected percentages of additives and woolswatches.

From the viewpoint of foaming generally, the novel compositions of thepresent invention are characterized by increased stability of the foamproduced in washing operations in comparison to the foaming effectsproduced by compositions without the additive. The foam of the presentcompositions has good creaminess and consistency, does not readily breakdown by evaporation, has in general a longer drainage time, and containsan increased amount of liquid.

It has also been found that the present combinations tend to increasethe tolerance of the detergent composition for the assimilation orholding in suspension of a maximum amount of dirt, grease, etc. withless foam loss than is found without the use of the desired additives.

In practical dishpan tests wherein greased dishes are washed by hand ina dishpan of water containing a small amount of the detergentcomposition, the compositions is considerably slower on solutions of thepresent com-..

positions than with corresponding solutions of the detergentcompositions without the desired additives.

Table IV discloses comparatively the average results.

in foam endurance or duration obtained in thedishwashing of variousgreased plates with two compositions. Formula A contains 25% sodiumsalts of coconut monoglyceride monosulfate detergent as the activeingredient, 10% diacid disodium pyrophosphate and 65% sodium sulfate. Asecond formula (B) has 3% dodecyl ureaadded thereto. The tests areconducted in hard water at cedure comprises conducting the pour foamtest in the presence of a small amount of soil. The pour foam test isdesigned for comparative study of the relative foam stability of liquidsand is set forth in U. S. Patent No. 2,315,983 to Ross and Miles. Thefoam height in millimeters of solutions tested in accordance with theRoss et al. patent at various time intervals is an indication of thefoam stability in the presence of soil.

The above test is conducted at 0.25% concentration of detergentcomposition in distilled water, using separately three compositions.Composition I is the detergent formula set forth in Table I containing20% sodium dodecyl benzene sulfonate, Composition II contains 1.5%dodecyl urea added to I, and Composition III has an active ingredientcontent of 35% and a corresponding reduction in the amount of sodiumsulfate is made accordingly. The following results are achieved:

Thus it may be noted that Composition II containing the urea typeadditive exhibits a high level of foam stability for the full timeinterval, whereas the foam generated by Formula I with no additivecollapsed completely within 5-10 minutes. The synergistic effect of theadditive herein is all the more striking in relation to the effectsachieved with Formula III containing a vastly increased activeingredient content.

It is common to employ various adjuvant materials in synthetic detergentcompositions. The detergent compositions of the present invention mayinclude any' of these substances employed bythe art in admixture 7 13*be a minimum of at least about with such detergent compositionsgenerally, provided the use of any such materials, does not completelyneutralize or remove the effect of the substituted urea type additivesin the relationship set forth. These adjuvant builders or additives maybe inorganic or organic in structure and may be mixed with the activeingredient ispreferred that the detersive compositions in particu late,form contain major amounts of alkaline builders, particularly theinorganic water soluble phosphates. The total amount of phosphatecompounds should usualand preferably from about 10 to about 80% by theweight of the detergent composition for optimum results. A detergentcomposition containing anamount of active ingred'ient of about 15 to 50%with the requisite minor proportion of substituted urea. additives andabout to about 60% total phosphate compounds, particularly whereinsodium tripolyphosphfite is present in, substan: tial quantitiesexhibits highly desirable properties In liquid detergents, the activeingredient should preferably be in the form of a highly water solublesalt, e. g. ammonium, mono-, diand triethanol amine salts. The liquiddetergent composition may be prepared in dilute or concentrated aqueoussolution with or without the presenceof a lower molecular weightaliphaticalcohol such as ethyl alcohol, propylene glycol, etc.

The following examples are additionally illustrative of the nature ofthe present invention and it will be understood that the invention isnot limited thereto:

Example I A detergent composition is prepared by forming about a 6.0%solids slurry containing on a solids basis about 35% sodium propylenetetramer benzene sulfonate salt, 40% sodium tripolyphosphate, 15% sodiumsulfate, 3% dodecyl urea, and the remainder minor amounts ofsodiumchloride, sodium hydroxide, sodium carboxy-methylcellulosc, etc.This slurry-is agitated at about 140 F. in a conventional soap crutcherto form a homogeneous mixture. The slurry is submitted to spray-drying-With heated air at a temperature of about 350 F. with a resultantmoisture loss of about 40%. The resulting composition is recovered inthe formof beads, and possesses a high degree of detersive andfoamingproperties in both hard and soft Water.

Example 11 Example III Usingthe procedure of Example I an improveddetergent composition is prepared from the following components: 20%sodium lauryl sulfate, 40% sodium ably determined by routine controls.

8 Example V Per cent Sodium coconut alcohol sulfates 16 Sodium chloride1 Sodium tripolyphosphate 38 Tetrasodiumpyrophosphate 15 Sodium sulfate2.! N dodecyl N hydroxyethyl urea 3 Example VI Per cent Sodiumdodecylbenzene sulfonate 9 Sodium lauryl sulfate 1 0 N dodecyl N methylurea 3* Sodium carboxymethylcellulose 0.5 Sodium carbonate 1.5 Sodiumsulfate 20 Sodium tripolyphosphate 44 Tetrasodium pyrophosphate 12Example VII Per cent Higher fatty acid amides of taurine derived from.

coconut oil 25 Sodium sulfate" 30 Sodium tripolyphosphate 42 Dodecylurea 3 Certain general conclusions are apparent from the many testswhich have been conducted to determine the. effectiveness of thesubstituted urea additives in the relationship set forth. The mostappropriate additive and its most effective concentration. a for eachparticular sul'-' phonated, or sulphated detergent composition may besuit.- In, each case the intendeduse (e. g. hard or soft water, rugshampoos or machine washing compositions, etc.) and the proper washing,conditions should be taken into. consideration in.

order to derive the maximum beneficial effects.

The term consisting essentially of as used in the.

definition of the ingredients present in the composition claimed isintended to exclude the presence .of other materials in such amounts asto interfere substantially with the properties and characteristicspossessed by the composition set forthbut to permit the presence ofother materials in such amounts as not substantially to effect saidproperties and characteristics adversely.

Although the present invention has'been described with reference toparticular embodiments and examples, it will be apparent to thoseskilled in the art that variations and modifications of this inventioncan be made and that equivalents can be substituted therefor Withoutdepart ing from the principles and true spirit of the invention.

Having described the invention what is desired, to be secured by LettersPatent is: r

1. An improved synthetic detergent composition-consisting essentially ofa detergent selected from the group consisting of the, water-solubleanionic organiosulphate and sulphonate detergents and a minorproportionof a. urea derivative represented by the formula:

wherein R is a higher alkyl radical of about 10 to about:

. 14 carbons, said minor proportion. being sufiicientto-irntripolyphosphate, 38% sodium sulfate, and 2% dodecyl urea.

Example IV Another suitable detergent composition is prepared bycompounding 25% sodium coconut monoglyceride sulfate, 10% diacid,disodium pyrophosphate, 62% sodium sulfate and 3% N decyl N hydroxyethylurea.

Other formulations productive of desired results are:

prove the soil removal power thereof.

wherein R is a higher alkyl radical, the amountof said urea compoundbeing sufiicient to enhance the effect of.

:said detergent composition in solution.

3. An improved synthetic detergent composition in particulate formconsisting essentially of a water-soluble higher alkyl aryl sulphonatedetergent salt and a urea compound represented by the formula:

wherein R is a higher alkyl radical, the proportion of said sulphonatesalts to urea compound being from about 50:1 to about 2:1 and sufiicientto enhance the effect of said detergent composition in solution.

4. An improved heat-dried synthetic detergent composition consistingessentially of about 10 to about 50% water-soluble alkyl aryl sulphonatedetersive salts, about 10 to about 80% Water-soluble alkali metalphosphates, and a substituted urea compound represented by the formula:

wherein R is a higher alkyl radical, the amount of said urea compoundbeing from about /2 to about 15% and L suflicient to enhance the effectof said detergent composition in solution.

5. An improved synthetic detergent composition consisting essentially ofa water-soluble aliphatic sulphated detergent, and a urea compoundrepresented by the formula:

wherein R is a higher alkyl radical, the proportion of said detergent tourea compound being from about 50:1

to about 2:1 and suflicient to enhance the eifect of said detergentcomposition in solution.

6. A detergent composition consisting essentially of a water-solubledetergent selected from the group consisting of the anionic organicsulphate and sulphonate detergents, and a minor proportion of a compoundselected from the group consisting of higher alkyl ureas having theformula:

RNHCONH2 wherein R is a higher alkyl radical, and theirnitrogensubstituted lower alkyl and lower alkylol derivatives sufficientto improve the soil removal power thereof.

7. A detergent composition consisting essentially of a water-solubledetergent selected from the group consisting of the anionic organicsulphate and sulphonate detergents, and about A to about 15% by weightof a compound selected from the group consisting of higher alkyl ureashaving the formula:

wherein R is a higher alkyl radical, and their nitrogensubstituted loweralkyl and lower alkylol derivatives.

8. A detergent composition consisting essentially of a water-solubledetergent selected from the group consisting of the anionic organicsulphate and sulphonate detergents, and a minor proportion of asubstituted urea derivative represented by the formula:

wherein R is an alkyl group of 10 to 14 carbon atoms. 11. A detergentcomposition consisting essentially of a water-soluble higher alkylsulfate detergent, and about /2 to about 15% by weight of a compoundrepresented by the formula:

RNHCONH2 wherein R is an alkyl group of 10 to 14 carbon atoms.

12. A detergent composition consisting essentially of a water-solublehigher fatty acid monoglyceride sulfate detergent, and about /2 to about15% by weight of a compound represented by the formula:

wherein R is an alkyl group of 10 to 14 carbon atoms.

References Cited in the file of this patent UNITED STATES PATENTSJacobson Aug. 17, 1937 Swain Aug. 5, 1941 Flett Apr. 24, 1945 FOREIGNPATENTS France Jan. 11, 1936

4. AN IMPROVED HEAT-DRIED SYNTHETIC DETERGENT COMPOSITION CONSISTINGESSENTIALLY OF ABOUT 10 TO ABOUT 50% WATER-SOLUBLE ALKYL ARYL SULPHONATEDETERSIVE SALTS, ABOUT 10 TO ABOUT 80% WATER-SOLUBLE ALKALI METALPHOSPHATES, AND A SUBSTITUTED UREA COMPOUND REPRESENTED BY THE FORMULA6. A DETERGENT COMPOSITION CONSISTING ESSENTIALLY OF A WATER-SOLUBLEDETERGENT SELECTED FROM THE GROUP CONSISTING OF THE ANIONIC ORGANICSULPHATE AND SULPHONATE DETERGENTS, AND A MINOR PROPORTION OF A COMPOUNDSELECTED FROM THE GROUP CONSISTING OF HIGHER ALKYL UREAS HAVING THEFORMULA